The adoptive transfer of tumor infiltrating lymphocytes (TIL) plus interleukin-2 (IL-2) into the autologous patient with metastatic melanoma can result in the objective regression of tumor (Rosenberg et al. (1988); Rosenberg et al. (1994)), suggesting that T cells play an important role in tumor rejection in vivo. To understand the molecular basis of T cell-mediated antitumor responses, effort has been directed toward the identification of tumor antigens recognized by T cells and has led to the identification of a number of genes encoding tumor antigens in human melanoma (Boon et al. (1994); Houghton (1994); Tsomides et al. (1994); Pardoll (1994); Rosenberg (1995); Wang et al. (1996a)). These antigens can be divided into several classes based on their expression pattern. The tumor antigens such as MAGE1, MAGE3, BAGE and GAGE are encoded by genes that are expressed only in tumor, testis and placenta, but not other normal human tissues are examples of this class (Van der Bruggen et al. (1991); Gaugler et al. (1994); Van D n Eyne et al. (1995); Boel et al. (1995)). The second class of antigens such as MART-1/Melan-A (Kawakami et al. (1994a); Coulie et al. (1994)), gp100 (Kawakami et al. (1994b)), tyrosinase (Brichard et al. (1993); Robbins et al. (1994)) and gp75/TRP-1 (Wang et al. (1995)) are differentiation antigens encoded by genes that are expressed only in melanocytes, melanomas, and normal retinal tissue. These latter antigens are non-mutated self proteins. However, several mutated antigens were also identified to be recognized by T cells, including CDK4 (Wolfe et al. (1995)), β-catenin (Robbins et al. (1996)) and MUM-1 (Coulie et al. (1995)).
Recently, the gp75 TRP-1 gene encoding a tumor antigen recognized by the HLA-A31 restricted TIL586 was cloned (Wang et al. (1995)), which was previously shown to have in vivo antitumor activity when infused along with IL-2 into the autologous patient with melanoma. Surprisingly, the peptide recognized by TIL586 was found to be derived from the gene product translated from an alternative open reading frame of the TRP-1 gene (Wang et al. 1996b)). Site-directed mutagenesis experiments indicated that the ATG start codon in the alternative open reading frame was essential for generating the epitope recognized by TIL586. Six of fifteen T cell clones established from the TIL586 cell line were capable of recognizing 586mel tumor cells as well as 586EBV B cells pulsed with the peptide ORF3P derived from the alternative open reading frame of the TRP-1 gene (Wang et al. (1996b)). However, some T cell clones isolated from the same TIL586 line did not recognized TRP-1 and its ORF3P peptide pulsed on 586EBV B cells, although they were capable of recognizing 586mel and A31+ melanocytes.
One object of the present invention relates to the identification of TRP-2 as a new tumor antigen recognized by T cells.
Another object of the present invention are peptide fragments of TRP-2 and variants thereof, which function as cancer peptides.
Yet another object of the present invention are nucleic acid sequences encoding TRP-2 and fragments thereof, which, when expressed in a cell produce tumor antigens.
Another object of the present invention is a pharmaceutical composition comprising TRP-2 peptides which stimulate T-cells to elicit an immunogenic response against tumors and cancers.
Yet another object of the present invention is a method of using the tumor antigen and cancer peptide(s) as a pharmaceutical composition for the prevention, detecting and treatment of cancers.
It is still another object of the invention to provide a method for diagnosing human pre-neoplastic and neoplastic cells and tissues.